Catheter depth gauge and method of use

A method for determining spacial parameters such as the linear distance from an object of interest within a body cavity or vessel, the method comprising the steps of:

• introducing into a body area to be examined a catheter having a proximal end and a distal end and including a hollow body and a hollow tubular member defining a lumen joining and extending distally of the body to a catheter tip;
• moving a cylindrical member having an outer wall with at least one marking on the outer wall and extending through the lumen of the catheter so that the tip of the cylindrical member extends distally of the catheter tip so as to move the tip of the cylindrical member away from the catheter tip and adjacent to the object of interest;
• comparing a marking on the outer wall of the cylindrical member with a transparent gauge in the body of the catheter at the proximal end of the catheter to record a first location of the marking relative to the gauge when the tip of the cylindrical member is adjacent the object of interest;
• moving the tip of the cylindrical member away from the object of interest;
• comparing the marking on the wall of the cylindrical member with the transparent gauge to record a second location of the marking relative to the gauge;
• and
• measuring the distance between the first and second locations representing the linear distance between the object of interest and the tip of the cylindrical member.

A method for determining spacial parameters such as linear distance in a body cavity or vessel, the method comprising the steps of:

• introducing into a body area to be examined a catheter having a proximal end and a distal end and including a hollow body and a hollow tubular member defining a lumen joining and extending distally of the body to a catheter tip;
• providing an endoscope having an image lens for viewing an object in the body region, means for emitting light from a tip of the endoscope and a light transmitting bundle for transmitting collected light to the proximal end of the catheter, the endoscope further having an outer wall with at least one marking on the outer wall;
• extending the endoscope through the lumen of the catheter so that the tip of the endoscope extends distally of the catheter tip;
• moving the tip of the endoscope away from the catheter tip and closer to an object of interest;
• observing the location of the marking on the endoscope outer wall relative to a transparent gauge in the body of the catheter at the proximal end of the catheter;
• moving the endoscope in the opposite direction while viewing an image of the object of interest;
• observing the location of the marking on the endoscope outer wall relative to a transparent gauge in the body of the catheter at the proximal end of the catheter;
• moving the endoscope in the opposite direction while viewing an image of the object of interest;
• discontinuing movement of the endoscope when the object of interest is in focus;
• and
• comparing the marking on the endoscope outer wall with the transparent gauge to measure the length of the endoscope that has passed through the hollow body past the transparent gauge.